An airbag flap system comprising a carrier and an airbag cover is part of an airbag device which, incorporated in an automotive vehicle, has the object of protecting persons from severe injury in the case of an accident. For this reason, it is generally common nowadays to incorporate one or more airbag devices in an automotive vehicle.
In addition to the airbag flap system with the airbag cover contained therein, further important components of an airbag device are the airbag and the airbag trigger. These components must fulfil various tasks. The airbag trigger has the object of inflating the airbag as rapidly as possible upon being triggered. The airbag cover separates the airbag in the initial state from the interior of the automotive vehicle. One or more airbag flaps are integrated in the airbag cover. The airbag flaps have the object of enabling unfolding of the airbag into the interior. The airbag cover is generally connected to a housing in which the airbag and the airbag trigger are accommodated and positioned under the airbag flaps.
Because of the great importance of protecting the occupants, it is necessary to ensure as perfect a function as possible of the airbag device. It must be ensured inter alia that the airbag flaps integrated in the airbag cover do not impede unfolding of the airbag too greatly in order not to reduce the protective effect of the airbag. In the case of airbag flaps integrated in the airbag cover, it must also be ensured that these do not detach from the carrier thereof or even burst when the airbag is unfolding in order not to endanger the occupants in addition.
It is known to produce airbag covers from a soft synthetic resin, e.g. thermoplastic elastomers, and to insert this airbag cover in a carrier made of hard synthetic resin, e.g. polypropylene, as an insert. Predetermined breaking points are provided in the airbag cover by means of which airbag flaps which open upon unfolding of the airbag are defined. The soft synthetic resin of the cover provides a hinging effect during opening of the flaps and hence prevents detachment from the carrier. Because of the elastic properties of the soft synthetic resin, bursting of the airbag flaps is counteracted also as it were.
A disadvantage when using a hard synthetic resin as carrier and a soft synthetic resin as cover is that the synthetic resins adhere to each other poorly.